Better path_to_c_string impl

compiler/rustc_fs_util/src/lib.rs

@@ -1,4 +1,3 @@
-#[cfg(any(unix, windows, target_os = "wasi"))]
 use std::ffi::CString;
 use std::path::{absolute, Path, PathBuf};
 use std::{fs, io};
@@ -77,14 +76,18 @@ pub fn link_or_copy<P: AsRef<Path>, Q: AsRef<Path>>(p: P, q: Q) -> io::Result<Li
     }
 }
 
-#[cfg(unix)]
+#[cfg(any(unix, all(target_os = "wasi", target_env = "p1")))]
 pub fn path_to_c_string(p: &Path) -> CString {
     use std::ffi::OsStr;
+    #[cfg(unix)]
     use std::os::unix::ffi::OsStrExt;
+    #[cfg(all(target_os = "wasi", target_env = "p1"))]
+    use std::os::wasi::ffi::OsStrExt;
+
     let p: &OsStr = p.as_ref();
     CString::new(p.as_bytes()).unwrap()
 }
-#[cfg(any(windows, target_os = "wasi"))]
+#[cfg(windows)]
 pub fn path_to_c_string(p: &Path) -> CString {
     CString::new(p.to_str().unwrap()).unwrap()
 }